The labels are needed because, “There’s no immediate signal to a consumer of gasoline to show their effects on climate,” Jamie Brooks told the San Francisco Chronicle. Brooks represents 350BayArea.org, the group behind the proposal.

Jack Lucero Fleck, who also represents 350 Bay Area, said he’s heard criticism that warning labels are ineffective and that the ills of climate change are already widely known. Fleck pointed out that a recent Yale University study found that only one in three people expect the effects of climate change hit them or their children, despite findings that major shifts will be seen over 40 years. He says the labels will function much as commercial advertising by “putting their message out in public.”

The Chronicle reports that the idea is being proposed to individual city governments, and that San Francisco and Berkeley officials have already been approached about the campaign. There was no timeline on when the labels could appear. If approved they would likely face legal challenges from the oil industry.